In cataract operations, removing an opacified lens by phacoemulsification (PEA) and implanting an intraocular lens after an opacified lens has been removed are widely performed. The types of intraocular lens include a hard intraocular lens with its optic area made of a hard material, such as PMMA, and a soft intraocular lens made of a soft material such as silicone elastomer or soft acrylic. When using a hard intraocular lens, the intraocular lens must be inserted through an incision in the cornea or sclera that is formed so as to have about the same width as the diameter of the optic area. On the other hand, when using a soft intraocular lens, folding of the optic area allows the intraocular lens to be inserted into the eye through an incision that is smaller than the diameter of the optic area. Inserting a lens from a small incision is desirable to reduce the post-surgery corneal astigmatism and infection, so there has been a trend in recent years to favor the soft intraocular lens. In addition, to insert the lens into the eye, there are cases where a special injector is used, said special injector having a structure provided with a long tube through which the lens passes as it is guided into the eye. Using such a special intraocular lens injector makes it possible to insert the lens through an incision smaller than 3 mm.
In addition, preset injectors having the lens set in the injector in advance to eliminate the risk of contamination by microbes during lens handing and of possible operational mistakes during lens handling have recently come to market. Some preset injectors are provided with a holding mechanism that holds the lens inside in a state that does not stress the optic area and with a lens movement mechanism that moves the lens to a position where it can be pushed out by an discharge device so as to transfer the lens from the lens immovable state during shipment to the lens movable state during use (For example, Patent Documents 1 and 2).
However, in the above patent documents 1 or 2, it is necessary to move the lens from the stationary position to a position where it can be pushed out during its use, and there is a fear of yielding operational mistake accompanying the movement operation. As a solution to such problems, there is disclosed an intraocular lens insertion device characterized in that a push-out shaft and a posture control member for preventing the shaft misalignment between the push-out shaft and a lens are arranged in a manner capable of interlocking with each other, and such mutual interlocking is released at a prescribed position (For example, Patent Document 3). In this patent document 3, it is necessary to provide a special mechanism for releasing at a predetermined position the interlocking between the two members: the push-out shaft and the posture control member that are interlocked with each other within a closed space or an injector. Further, there is disclosed another intraocular lens insertion device characterized in comprising a mechanism for laterally compressing a flexible intraocular lens into a small cross-sectional configuration (For example, Patent Document 4).    Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No. 2003-325570    Patent Document 2: JP-A No. 2003-325572    Patent Document 3: JP-A No. 2004-24854    Patent Document 4: JP-A No. 2001-502563